Safety attachment for scaffolds.



F. STILLWELL.

SAFETY ATTACHMENT FOR SCAFFOLDS.

APPLICATION FILED DEC. 16. 1914.

1,148,872. Patented Aug. 3, 1915.

5 vwe wto'c Hank Sully/ell,

. 5&1 I: is Show mg ,7 2

\FRANK srILLwnLn; or BROOKLYNQNEW YORK.

was

ToaZZ whom it may concern: I l

Be it known thatI, FRANK s'rrLLwnLLpa citizen ofithe United States,anolresiding at Brooklymin thecounty of Kings and Stateof New York, haveinvented certain new and useful Improvements in Safety Attachments forscaffolds, of which the followingis a specification, such as will enablethoseskilled in the artto which 'it appertains to make and use :thesame.

This invention relates to safety deviceson attachments foruse inconnectionwith scaffolds, and the object thereof is to provide animproveddeviceof this class which is simple in construction andefiicient 'in operation and which will prevent the droppingor fallingofascalfold in case" the suspending cords'or cables should break,

and with this and other objects in viewthe invention consists in adevice or apparatus ofthe class specified, constructed and operating ashereinafter described; #1 Li J i The invention is fully disclosed in thefollowing specification, of "which the accompanying drawing forms apart, in which the separate parts-of my improvement are 'deslgnated bysuitable reference characters m each of the views, and in which 2+Figure 1 is a side view of a part of a,

scaffold and showing my improvement applied thereto; Fig. 2 a section onthe line 2-2 of Fig. 1 and showing the parts in their normal position;Fig. 3 a view similar to Fig. 2 butshowingthe position the parts assumeif. the supporting rope or cable should break;

Fig. l a partial section on the line H of Fig. 2; and, Figs. 5 and 6 aresectional views of a detail of tl'l8' COIlstruction.

In the drawing forming part of this specification, I have shown at a apart of a scaffold, consisting of top and bottom members a and aconnected as shown at a but it will be understood that the scaffold maybe of any preferred construction. I hav-e also shown in said figure apulley block Z) connected with the scaffold and a similar pulley block 5connected with the pulley block b by the usual rope or cable 0 and, inpractice, the pulley block b is suspended from any suitable overheadsupport (23.

The pulley blocks Z2 and 5 in the form of construction shown, areordinary double and single pulley blocks and are provided with pulleywheels 6 and saidpulley blocks are Specification of Letters Patent.

wheels 6" provided with SAFETY Armour/mun i onscerronns.

Patented Aug. 3, 1915.

Application filed December 16;"1914. "serial No. 877,465.

also provided with yokes b which are loosely connected with shafts Z2Tcentrically through the/ pulley blocks b and passed ,ec-

Zfi, and on which aremounted eccentric cam projecting teeth N.

The yokes bof the separate pulley blocks are connected by a cord 6 whichis secured to the yoke of the upper pulley block b at e and detachablyconnected with the .yoke of the lower pulley block at 6 and thisconnection may be broken in the operation of a 'scafl'old and. thelength ofthe cord 6 adjustedso as to provide for the ver tical movementor adjustment of the scaffold. M l

t The shafts of. the cam wheels I) pass I through rectangular openings 5in the sides of the pulley blocks as shown in Figs. 4,

5 andf6, andin th e opposite sides of said slots vare placed arc-shaped.springs f, and

inthe, normal position of the parts the shafts b are held inthetop partsof the :open'ings min the toppulley block b and any; the bottom T partof the corresponding openings in the bottom pulley block b. *[The topandbottom 'parts of the pulley blocks are preferably provided withdepending pins or projections 19 in connection with which the teeth ofthecam wheels 6 operate under certain conditions ashereinafterdescribed. With-this construction, when the apparatusis in use, the end0 of the rope or cable 0 is detachably connected with the scaffold at 0and, if at any time, said rope or cable should break as shown at 0 inFig. 3 and the rope or cable should start to pull through the pulleyblocks in the direction of the arrows w in said figure, the cord 6 wouldoperate at once to move the cam wheels 6 of the separate pulley blocksin the direction of the pulley wheels 6 and the teeth 6" of said camwheels would engage the rope or cable as shown in Fig. 3, and said camwheels would be thrown into operation and would grasp and hold the saidrope or cable and prevent its movement through the pulley blocks andthis, as would be understood would prevent the dropping or falling ofthe scaffold.

In order to raise or lower the scaffold the ends a of the rope or cable0 must be detached from the scaffold and manipulated in the manner ofother devices of this class 7 operation of raislng the scaffold aftersaid scaffold has been raisedby the manipulationand slackened and againsecured, and 7 of the end portion the cord 6 must readilyunderstood. v

In Fig. 1 of the accompanying drawing,

of therope or cableic that part of the rope'ion cable: 0 iwhichsis;

the loWer pulley block is shown-in dottedrlines only so as 1120* notconconnected With fusecthe drawing; a and. so as to show the methodiofoperating the cord- 6, but it will beunderstood that 'the I rope orcable: 0. 'is

connected: wWlt/hfithe pulley blocks 6 and? b intheusual manner.

Inv the operationof ,apparatusbof' this classit :is ;possible for;foreign substances to become "connected with the cable 0, and "when saidsubstances pass :betvveen'the cam wvheels Zfifiil'ldJthQcorresponding:pulleyi'wheels they :might operate saidlcam :Wheels;andzthe' pins orprojections $6 an thevapulleiyblocks are designed topreventtsuch; operation, but these can wcmsipaxemma bembt'ainedsfor insor projections Will not interferewith the operation of saidicazmWheels-fasherein described, in case the :rope or: cable 2c; shouldbreak.-. r v g My. invention is 1-.not limitedto; the use of thearc-shaped? springs and other formsmf, springs-may be? employedforthisipurpose, nor is my invention "limited to adoubleypulley; block,or 'to pulq .lerbl c details "of construction herein ,be made,.,vvithinthe scope of the appended be tightened as Will" be block,

- movable toward therein;

f for holding; the shafts b and-cam wheels-b outiof; operation of anyspecific construction, and various changesin and modifications of thedescribed may claim, Withoutdeparting from the spirit of my invention orsacrificing its advantages.

Having fully described my invention, Whatwli claiimas-newi and desire tosecure by Letters Patent, is

A scaifold device; provided withfaspulle'y another pulley blockada-ptedto be connected. with an overhead support, said pulley blocks being"provided .with. pulley wheels onwhich is mounted a .rope or: cable bywhich saidwblocksare connected cam Y Wheels-mounted; inthe bottomportion ofthe pulley block connected vwith the scafiold and andfrom'theipulleygwheels movable toward and from the-;pulley Wheels cam;Wheels of both blocks...

I as mypinvention ,I-=.havea signed. my-name1n presence 1 of? thesubscribing Witnesses .this leth dayiiofzDecember 191e,. I

FRANKSTILLWELL;

Witnessesk; g G.. MULREA 1 IX," r i EQTTHQMPSQNL fiveic'ents leach rbyaddressinaithc commissioncri of intents, Washington, 1G3

other cam Wheelsmounted in the itopiiportionofgthe pulley block adaptedto -beiconnected' with an overhead support and ina'saidvblock,andsmeansffori connecting the

